Modify 24 pin SMPS to Dell Optilex 8 pin SMPS

Hello guys today I am going to share an intelligent idea of Modifying
general 24 pin SMPS to Dell optilex 3020/ 7020 / 9020 / T1700 SMPS
model i.e 8 pin.
This idea came to me when mine office Dell
optilex 3020 SMPS was fired by surge voltage from short circuit. First,
I tried with replacing another new SMPS of same model but due to
unavailability in market I prefer of hacking 24/20 port SMPS which was
easily available.

24 pin SMPS

1st step:
Map
the both SMPS pin configuration. I google the 24 pin SMPS pin
configuration and found out but I couldn't found out the 8 pin SMPS
configuration so I measured voltage and signal with multi meter from
another working Optilex SMPS and found out those pin configuration.

Then,
now we are going to do a intelligent trick as there is no 12v stand by
voltage (VSB) pins in 24 pin SMPS as there is +5v VSB. There are two
tricks for that.
First is to use voltage shifter IC to shift
voltage from +5v VSB to +12v VSB, which needs IC and other electronics
so why to do it if there is simple trick. :)
Second is to use
another +12v supply (yellow wire from 24 pin SMPS) as +12v VSB in 8 pin
SMPS. But, doing only these can run your PC. Yes or No?Answer
is NO. The main hack lies here. To run a PC, firstly the SMPS must give
the output to the PC_ON signal(green wire) and Voltage Standby (VSB)
and after the PC_ON signal is grounded then only the SMPS gives output
to other remainig pins. So the 12v (yellow wire) we have used only
turns ON after the PC_ON signal is grounded. So in order to firstly
output through the +12v pins short the PC_ON(green wire) signal to
ground(black wire).After doing this your connection must be as below :

2 yellow wires (24 pin) --> 2 white wires (8 pin)

3 black wires (24 pin) --> 3 black wires (8 pin)

1 grey wire (24 pin) --> 1 grey wire (8 pin)

1 yellow wires (24 pin) --> 1 purple wire (8 pin)

Short green and black wire (24 pins)

Green and Black wire Short.

4th step:
Finally now it is time to assemble and in your PC and test it.
After
giving power to PC instantly your CPU and SMPS fan runs and you may
worry. But, don't worry it is due to the short done with green and black
wire. But your PC motherboard gets power only after you switch on the
power button on CPU. So, you can happily use your PC.

Final SMPS

Happy Hacking !

This article/tutorial is written by Sushan Baskota, ICTV DDC Panchthar. For feedback, please comment on the article below.

About Author (sushan baskota)

This portal "ICT for Local Bodies" is written by various individuals - ICT Experts and ICT Volunteers working under MoFALD/LGCDP with an aim of integrating ICT at Local Governance. The author is this post is mentioned at the end of the article itself (with their Google+ profile alongside). Learn more about ICT4LB KMDB here.